Average quality. The instructions provided inside are not correct. You need to leave it in hot water for a longer time. The red material is not the same as the black one, it is much softer, supposedly to deform when it comes into contact with hot water, but when you bite it, it spreads outside the mouthguard, resulting in it being uncomfortable in your mouth when you wear it. Most importantly, it does not stay on the upper teeth without biting, causing it to fall off and come out.